Star-Shaped Polycyclic Aromatics Based on Oligothiophene-Functionalized Truxene:  Synthesis, Properties, and Facile Emissive Wavelength Tuning

• Published in: Journal of the American Chemical Society 2003-08, Vol.125 (33), p.9944-9945
• Main Authors: Pei, Jian, Wang, Jin-Liang, Cao, Xiao-Yu, Zhou, Xing-Hua, Zhang, Wen-Bin
• Format: Article
• Language: English
• Subjects: Applied sciences; Exact sciences and technology; Organic polymers; Physicochemistry of polymers; Polymers with particular structures; Preparation, kinetics, thermodynamics, mechanism and catalysts
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja0361650

A facile approach to soluble star-shaped oligothiophene-functionalized polycyclic aromatics based on truxene is developed in this Communication. The Suzuki coupling reactions afford the thiophene-containing polycyclic aromatics with long branches (about 2.1 nm length from the heart to the periphery) from truxene precursor with excellent yields. The unsubstituted α-positions of thiophene rings allow for efficient halogenation and for further functionalization. The investigation of proton NMR spectra indicates that the hexahexyl groups efficiently prevent the self-association through the arene−arene π-stacking. Chemical shifts belonging to methylene groups move more upfield than do those of methyl groups. These chemical shift values (about 0.5−0.6 ppm) are quite lower than those of normal methyl and methylene groups. We also prepare a dendritic hyperbranched polymer P1 through FeCl3 mediated oxidative polymerizations. The photophysical properties of all compounds possessing good symmetry are investigated by UV−vis and emission measurement.